1. Technical Field
The present invention relates generally to foam generating apparatus and methods of applying foam produced by said apparatus, including the application of insecticidal foams for the treatment of insects. The present invention also has a particular application in the field of treating fire ants.
2. Background Art
There are numerous apparatus available for generating foams for various applications. Such applications include, for example, cleaning, fire extinguishing, chemical containment, and insect treating. Many of these apparatus require electric or gasoline power sources for operating compressors and pumps to produce and deliver the foam. As a result, these apparatus must carry batteries, electrical cords, internal combustion engines, and the like. Examples of such devices are described in U.S. Pat. No. 5,319,878 to Moffett et al.; U.S. Pat. No. 5,346,699 to Tiernan et al.; U.S. Pat. No. 4,688,349 to Renth; U.S. Pat. No. 3,618,856 to Sachnik; U.S. Pat. No. 3,589,054 to Pascucci; and a product brochure published by B&G Equipment Company, Plumsteadville, Pa., entitled, Trouble-Shooter Portable Foaming and Liquid Borate Unit. Such apparatus are expensive, cumbersome, and they usually require training to operate and specialized maintenance.
Inexpensive and easy to operate apparatus, employing manual pumps, have been used to produce foam for cleaning applications. For example, U.S. Pat. No. 5,222,633 to Blake, U.S. Pat. No. 2,653,848 to Lee, and a product catalog by The Fountainhead Group, Inc., New York Mills, N.Y., entitled, Professional Applicators Catalog ("Convenience Applicator"), all describe such foaming devices. However, the utility of these devices are limited to cleaning applications. Such devices are not suitable for producing and delivering foams for other applications, such as the treatment of insects.
The application of insecticidal foams for the treatment and control of insects has been known for a number of years. For example, U.S. Pat. No. 4,822,613 to Rodero describes an insecticidally-active foam for producing a positive insect barrier in a cavity. U.S. Pat. No. 5,346,699 to Tiernan et al. describes an insecticidal foam for treating termites under concrete slabs or around concrete foundations. Other insecticidal foams are described in U.S. Pat. No. 5,116,618 to Hagarty, U.S. Pat. No. 5,104,658 to Hagarty, U.S. Pat. No. 5,094,853 to Hagarty, U.S. Pat. No. 4,975,425 to Barnett, Jr., U.S. Pat. No. 4,889,710 to Hagarty, and U.S. Pat. No. 3,524,911 to Leavitt. The apparatus suggested for the application of these foams are aerosol cans, spray pumps like those used for household cleaners, spray guns, and electric or gasoline powered pumps. As mentioned previously, the electric or gasoline powered apparatus are expensive, cumbersome, and usually require training and specialized maintenance. Aerosol cans and household spray pumps suffer from the drawback that they do not hold a large capacity of foam composition. In addition, household spray pumps would require constant trigger pumping for most insect treating applications. Finally, spray guns do not suggest any advantages over such apparatus. None of these insecticidal foam patents suggests a suitable apparatus for treating ants inside the ant mound.
The injection of liquid insecticides (rather than foam) into ant mounds has been accomplished by using apparatus as described in U.S. Pat. No. 4,624,070 to Query et al. and U.S. Pat. No. 1,290,544 to Graumann. This method of treating ants is much less efficient than employed by the present invention because liquid insecticide is absorbed by the soil and is thus drawn away from the tunnels and chambers inside the mound. Penetration of the insecticide is also limited because of absorption. As a result, much more liquid insecticide is needed to treat an ant mound than if an insecticidal foam is employed. This leads to waste and an increased threat to the environment. Moreover, the apparatus proposed in U.S. Pat. No. 4,624,070 to Query et al. and U.S. Pat. No. 1,290,544 to Graumann are not very portable or convenient to operate.
Another aspect of the present invention pertains to applying an insecticidal barrier around a structure, such as dwelling. Conventional methods of producing such a barrier involve spraying liquid insecticides along the target area. Liquid spraying can be inefficient when laying down a barrier, because some of the sprayed contents may be blown away before reaching the ground or other target area. In addition, a sprayed liquid barrier is virtually invisible, and thus makes it difficult for the operator to determine whether the barrier has been properly laid down. An insecticidal foam has been proposed to avoid some of these drawbacks in U.S. Pat. No. 4,997,592 to Woogerd. However, this patent does not suggest the use of foaming apparatus that avoid the problems and drawbacks hereinabove mentioned.